/**
 *    Copyright (C) 2022-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include <memory>

#include "mongo/base/string_data.h"
#include "mongo/bson/bsonelement.h"
#include "mongo/bson/bsonmisc.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/db/change_stream_change_collection_manager.h"
#include "mongo/db/change_stream_serverless_helpers.h"
#include "mongo/db/commands/server_status.h"
#include "mongo/db/operation_context.h"

namespace mongo {
/**
 * Adds a section 'changeCollections' to the serverStatus metrics that provides aggregated
 * statistics for change collections.
 */
class ChangeCollectionServerStatus final : public ServerStatusSection {
public:
    using ServerStatusSection::ServerStatusSection;

    bool includeByDefault() const override {
        return true;
    }

    void appendSection(OperationContext* opCtx,
                       const BSONElement& configElement,
                       BSONObjBuilder* result) const override {
        // Append the section only when running in serverless.
        if (!change_stream_serverless_helpers::isChangeCollectionsModeActive()) {
            return;
        }

        auto& changeCollectionManager = ChangeStreamChangeCollectionManager::get(opCtx);
        result->append(getSectionName(),
                       BSON("purgingJob" << changeCollectionManager.getPurgingJobStats().toBSON()));
    }
};
auto& changeCollectionServerStatus =
    *ServerStatusSectionBuilder<ChangeCollectionServerStatus>("changeCollections").forShard();

}  // namespace mongo
